This review of existing regulations is being conducted in response to a petition for reconsideration and a request for an administrative stay we received by the Environmental Defense Fund (EDF), the Natural Resources Defense Council (NRDC), the Environmental Integrity Project (EIP), the Sierra Club, and the Adirondack Council (“petitioners”) on EPA’s November 24, 2020, final rule titled, “Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NNSR): Project Emissions Accounting” (85 FR 74890) (“Project Emissions Accounting rule”). Therefore, the Agency at its own discretion, is finalizing revisions to the EPA NSR regulations that would address the issues raised in the submitted petition and some related comments received on the Project Emissions Accounting rule.